%0 Journal Article %1 Ghumaan.2005b %A Ghumaan, Sandeep %A Sarkar, Biprajit %A Patra, Srikanta %A van Slageren, Joris %A Fiedler, Jan %A Kaim, Wolfgang %A Lahiri, Goutam Kumar. %D 2005 %J Inorganic Chemistry %K EPR complex dinuclear oxidn phenanthrolinediimine phenanthrolinediimine;ruthenium phenanthrolinedione prepn ruthenium spectroelectrochem state unsym %N 9 %P 3210--3214 %R 10.1021/ic048309x %T Sensitive Oxidation State Ambivalence in Unsymmetrical Three-Center (M/Q/M) Systems (acac)2Ru(m-Q)Ru(acac)2n, Q = 1,10-Phenanthroline-5,6-dione or 1,10-Phenanthroline-5,6-diimine (n = +, 0, -, 2-) %V 44 %X The new redox systems (acac)2Ru(m-Q1)Ru(acac)2n (1n) and (acac)2Ru(m-Q2)Ru(acac)2n (2n) with Q1 = 1,10-phenanthroline-5,6-dione and Q2 = 1,10-phenanthroline-5,6-diimine were studied for n = +, 0, -, and 2- using UV-visible-NIR spectroelectrochem. and, in part, EPR and susceptometry. The ligands can bind the first metal (left) through the phenanthroline N atoms and the second metal (right) at the o-quinonoid chelate site. The neutral compds. are already different: Compd. 1 is formulated as a RuII(m-Q1).bul.-RuIII species with partially coupled semiquinone and Ru(III) centers. In contrast, a RuIII(m-Q2)2-RuIII structure is assigned to 2, which shows a weak antiferromagnetic spin-spin interaction (J = -1.14 cm-1) and displays an intense half-field signal in the EPR spectrum. The 1-electron reduced forms are also differently formulated as RuII(m-Q1)2-RuIII for 1- with a RuIII-typical EPR response and as RuII(m-Q2).bul.-RuII for 2- with a radical-type EPR signal at g = 2.0020. In contrast, both 12- and 22- can only be described as RuII(m-Q)2-RuII species. The monooxidized forms 1+ and 2+ show very similar spectroscopy, including a RuIII-type EPR signal. Although no unambiguous assignment was possible here for the alternatives RuII(m-Q)0RuIII, RuIII(m-Q)2-RuIV or RuIII(m-Q).bul.-RuIII, the last description is favored. The reasons for identical or different oxidn. state combinations are discussed. on SciFinder(R)

@article{Ghumaan.2005b, abstract = {The new redox systems [(acac)2Ru(\textgreek{m}-Q1)Ru(acac)2]n (1n) and [(acac)2Ru(\textgreek{m}-Q2)Ru(acac)2]n (2n) with Q1 = 1,10-phenanthroline-5,6-dione and Q2 = 1,10-phenanthroline-5,6-diimine were studied for n = +, 0, -, and 2- using UV-visible-NIR spectroelectrochem. and, in part, EPR and susceptometry. The ligands can bind the first metal (left) through the phenanthroline N atoms and the second metal (right) at the o-quinonoid chelate site. The neutral compds. are already different: Compd. 1 is formulated as a RuII(\textgreek{m}-Q1).bul.-RuIII species with partially coupled semiquinone and Ru(III) centers. In contrast, a RuIII(\textgreek{m}-Q2)2-RuIII structure is assigned to 2, which shows a weak antiferromagnetic spin-spin interaction (J = -1.14 cm-1) and displays an intense half-field signal in the EPR spectrum. The 1-electron reduced forms are also differently formulated as RuII(\textgreek{m}-Q1)2-RuIII for 1- with a RuIII-typical EPR response and as RuII(\textgreek{m}-Q2).bul.-RuII for 2- with a radical-type EPR signal at g = 2.0020. In contrast, both 12- and 22- can only be described as RuII(\textgreek{m}-Q)2-RuII species. The monooxidized forms 1+ and 2+ show very similar spectroscopy, including a RuIII-type EPR signal. Although no unambiguous assignment was possible here for the alternatives RuII(\textgreek{m}-Q)0RuIII, RuIII(\textgreek{m}-Q)2-RuIV or RuIII(\textgreek{m}-Q).bul.-RuIII, the last description is favored. The reasons for identical or different oxidn. state combinations are discussed. [on SciFinder(R)]}, added-at = {2022-06-15T11:26:56.000+0200}, author = {Ghumaan, Sandeep and Sarkar, Biprajit and Patra, Srikanta and {van Slageren}, Joris and Fiedler, Jan and Kaim, Wolfgang and Lahiri, Goutam Kumar.}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/2c667a58e5aeec47917babf1ccda86a5c/huebleriac}, doi = {10.1021/ic048309x}, interhash = {b9a51e090dca12569f4cd3d0d0a0c0da}, intrahash = {c667a58e5aeec47917babf1ccda86a5c}, issn = {0020-1669}, journal = {Inorganic Chemistry}, keywords = {EPR complex dinuclear oxidn phenanthrolinediimine phenanthrolinediimine;ruthenium phenanthrolinedione prepn ruthenium spectroelectrochem state unsym}, number = 9, pages = {3210--3214}, timestamp = {2022-06-15T09:26:56.000+0200}, title = {Sensitive Oxidation State Ambivalence in Unsymmetrical Three-Center (M/Q/M) Systems [(acac)2Ru(\textgreek{m}-Q)Ru(acac)2]n, Q = 1,10-Phenanthroline-5,6-dione or 1,10-Phenanthroline-5,6-diimine (n = +, 0, -, 2-)}, volume = 44, year = 2005 }